CVE-2023-53694
NONEDescription
In the Linux kernel, the following vulnerability has been resolved:
riscv: ftrace: Fixup panic by disabling preemption
In RISCV, we must use an AUIPC + JALR pair to encode an immediate,
forming a jump that jumps to an address over 4K. This may cause errors
if we want to enable kernel preemption and remove dependency from
patching code with stop_machine(). For example, if a task was switched
out on auipc. And, if we changed the ftrace function before it was
switched back, then it would jump to an address that has updated 11:0
bits mixing with previous XLEN:12 part.
p: patched area performed by dynamic ftrace
ftrace_prologue:
p| REG_S ra, -SZREG(sp)
p| auipc ra, 0x? ------------> preempted
...
change ftrace function
...
p| jalr -?(ra) <------------- switched back
p| REG_L ra, -SZREG(sp)
func:
xxx
ret
Affected routers (1)
| Vendor | Model | Matched via | Affected versions | Fixed in | Patch? |
|---|---|---|---|---|---|
| Ubiquiti | Ubiquiti EdgeRouter 4 | — |
— | — | No |